A Hakka walled village (Chinese: 围龙屋) is a large multi-family communal living structure that is designed to be easily defensible.
As rivalry for resources turned to armed warfare, the Hakka began building communal living structures designed to be easily defensible.
These houses, sometimes called tulou 土楼, were often round in shape and internally divided into many compartments for food storage, living quarters, ancestral temple, armoury etc.
Researchers note similarity between some of the walled villages and some ancient fortifications in southern China, as seen in Han dynasty and Three Kingdoms tomb models unearthed in Guangzhou, Guangdong[1] and in Ezhou, Hubei.
The Hakkas who settled in mountainous south western Fujian province in China developed unique architectural buildings called tulou, literally meaning earthen structures.
Unlike their kin in Fujian, the Hakkas in Xingning (兴宁, Hin Nin) and Meixian (梅县, Moi Yen) developed non-fortress-like architectural styles, typified most notably by the weilongwu (Chinese: 围龙屋; pinyin: wéi-lóng-wū) and sijiaolou (Chinese: 四角楼; pinyin: sì-jǐao-lóu).